Barium titanate based semiconductor porcelain which is applicable to the laminated PTC thermistor element mentioned above is described in, for example, Patent Document 1 below. This barium titanate based semiconductor porcelain is 0.9 μm or less in average porcelain grain size, 90 Ωcm or less in resistivity at room temperature (25° C.), and 720 V/mm or more in withstanding voltage intensity.
Patent Document 1: Japanese Patent Application Laid-Open No. 11-116327